An electrostatic prevention structure using a grounding tread to discharge static electricity generated during vehicle travel through a pneumatic tire to a road surface is known in the art. In this electrostatic prevention structure, the grounding tread is exposed to a road contact surface of a tread rubber and is disposed so as to penetrate a cap tread and an undertread to contact a belt layer in an electrically conductive manner. As a result, static electricity from the vehicle side is discharged from the belt layer through the grounding tread to the road surface so that electrification of the vehicle is prevented. The technologies described in Japanese Patent No. 3287795 and Japanese Patent No. 3763640 are conventional pneumatic tires using such a configuration.